1. Field of the Invention
The present invention relates to a control system for a power steering motor of a power steering system for use with a battery operated vehicle, such as a battery operated forklift.
2. Description of the Prior Art
A power steering system for a battery operated vehicle such as a forklift typically has a drive motor for a hydraulic pump (referred to hereinafter as a power steering motor). Such power steering motors are generally supplied with electric power through a wheel drive motor control circuit.
Specifically, the control circuit for the wheel drive motor may include two pair of relay switches connected between a battery and the wheel drive motor, and operated by a forward movement switch and a reverse movement switch to permit manual selection of the direction of movement of the vehicle. In addition, the power steering motor may be connected to one of the relay switches in order to receive current from the battery through the control circuit for the wheel drive motor.
This type of control system, suffers from a disadvantage in that the operation of the power steering system may be effected only when the forward movement switch or the reverse movement switch of the control circuit is closed or active. In other words, the power steering system is rendered inoperative when the battery operated vehicle is coasting or stationary and both of the forward movement switch and the backward movement switch are open or inactive.